The present invention relates to an apparatus for detecting circulating liquid flow of a processing tank in a machine for automatically processing a photographic light-sensitive element.
Machines for automatically processing photographic light-sensitive material (hereinafter sometimes referred to as "automatic processing machines") are arranged in various ways in accordance with the kind of light-sensitive material. For example, in the automatic developing machine, a black-and-white developing tank, a fixing tank, and a water-washing tank are provided in the case of a black-and-white photographic light-sensitive material, while a coloring developing tank, a decoloring tank, a fixing (or bleach fixing) tank, and a water-washing or fixing tank are provided in the case of a color photographic light-sensitive material. Then, an image-exposed light-sensitive material is successively led into the above-mentioned various processing tanks, processed in the processing tanks, and then discharged after being dried.
Further, in an automatic processing machine, when processing of a light-sensitive material has been completed, the activity of the processing liquids is reduced. In order to recover the, processing liquids, generally, a system is used in which the processing tanks are provided with replenishing liquid tanks for replenishing the processing liquids respectively, so that when light-sensitive materials are led into the automatic processing machine, the replenishing liquids are supplied in accordance with the quantity of the light-sensitive materials. Further, in order to equalize the compositions of the processing liquids or temperature distribution of the processing liquids in the respective processing tanks, circulating pumps for circulating and stirring the processing liquids are provided outside the respective processing tanks.
Recently, as the time required for processing the photographic material has become shorter, a processing temperature is made high to about 25.degree. C.-40.degree. C. so that the time taken for processing by the processing liquid is made short. In order to raise the temperature of the processing liquid to a predetermined value, a heater is provided in a processing tank, or heating means such as a heat exchanger, a heater, or the like is provided in a path of a circulating system by means of the above-mentioned circulating pump.
In the latter system, generally, the processing liquid is sucked by the circulating pump from a lower portion or a bottom portion of the processing tank, heated to a predetermined temperature, and then returned into the processing tank. In this case, however, precipitation in the processing tank often blocks the circulating piping system or the circulating pump, or the circulation is often stopped or weakened owing to a malfunction of the pump or the like, so that the temperature of the treatment liquid cannot be raised to the predetermined value, or the mixing of the processing liquid becomes insufficient to give significant influence to the processing. Conventionally, however, there has been no simple device or system for automatically detecting such a malfunction in the circulating system.